From 35fe6d763229e8fc0eb5f9b93a401673cfcb5e1e Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 12 Jul 2017 11:49:56 -0700 Subject: [PATCH] block: use standard blktrace API to output cgroup info for debug notes Currently cfq/bfq/blk-throttle output cgroup info in trace in their own way. Now we have standard blktrace API for this, so convert them to use it. Note, this changes the behavior a little bit. cgroup info isn't output by default, we only do this with 'blk_cgroup' option enabled. cgroup info isn't output as a string by default too, we only do this with 'blk_cgname' option enabled. Also cgroup info is output in different position of the note string. I think these behavior changes aren't a big issue (actually we make trace data shorter which is good), since the blktrace note is solely for debugging. Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- block/bfq-iosched.h | 13 ++++++++----- block/blk-throttle.c | 6 ++---- block/cfq-iosched.c | 15 ++++++--------- include/linux/blktrace_api.h | 13 +++++++++---- kernel/trace/blktrace.c | 12 ++++++++++-- 5 files changed, 35 insertions(+), 24 deletions(-) diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 63e771ab56d8..1f74d71b45cd 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -917,13 +917,16 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); struct bfq_group *bfqq_group(struct bfq_queue *bfqq); #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ - blk_add_trace_msg((bfqd)->queue, "bfq%d%c %s " fmt, (bfqq)->pid,\ - bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \ - bfqq_group(bfqq)->blkg_path, ##args); \ + blk_add_cgroup_trace_msg((bfqd)->queue, \ + bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \ + "bfq%d%c " fmt, (bfqq)->pid, \ + bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \ } while (0) -#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) \ - blk_add_trace_msg((bfqd)->queue, "%s " fmt, (bfqg)->blkg_path, ##args) +#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \ + blk_add_cgroup_trace_msg((bfqd)->queue, \ + bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \ +} while (0) #else /* CONFIG_BFQ_GROUP_IOSCHED */ diff --git a/block/blk-throttle.c b/block/blk-throttle.c index a6ebd2bdb4df..6a4c4c493dd5 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -373,10 +373,8 @@ static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw) if (likely(!blk_trace_note_message_enabled(__td->queue))) \ break; \ if ((__tg)) { \ - char __pbuf[128]; \ - \ - blkg_path(tg_to_blkg(__tg), __pbuf, sizeof(__pbuf)); \ - blk_add_trace_msg(__td->queue, "throtl %s " fmt, __pbuf, ##args); \ + blk_add_cgroup_trace_msg(__td->queue, \ + tg_to_blkg(__tg)->blkcg, "throtl " fmt, ##args);\ } else { \ blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \ } \ diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3d5c28945719..0fb78fb3c03c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -656,20 +656,17 @@ static inline void cfqg_put(struct cfq_group *cfqg) } #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \ - char __pbuf[128]; \ - \ - blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \ - blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \ + blk_add_cgroup_trace_msg((cfqd)->queue, \ + cfqg_to_blkg((cfqq)->cfqg)->blkcg, \ + "cfq%d%c%c " fmt, (cfqq)->pid, \ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ - __pbuf, ##args); \ + ##args); \ } while (0) #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \ - char __pbuf[128]; \ - \ - blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf)); \ - blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args); \ + blk_add_cgroup_trace_msg((cfqd)->queue, \ + cfqg_to_blkg(cfqg)->blkcg, fmt, ##args); \ } while (0) static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index d2e908586e3d..67b4d4dfc19c 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -28,10 +28,12 @@ struct blk_trace { atomic_t dropped; }; +struct blkcg; + extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *); extern void blk_trace_shutdown(struct request_queue *); -extern __printf(2, 3) -void __trace_note_message(struct blk_trace *, const char *fmt, ...); +extern __printf(3, 4) +void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, const char *fmt, ...); /** * blk_add_trace_msg - Add a (simple) message to the blktrace stream @@ -46,12 +48,14 @@ void __trace_note_message(struct blk_trace *, const char *fmt, ...); * NOTE: Can not use 'static inline' due to presence of var args... * **/ -#define blk_add_trace_msg(q, fmt, ...) \ +#define blk_add_cgroup_trace_msg(q, cg, fmt, ...) \ do { \ struct blk_trace *bt = (q)->blk_trace; \ if (unlikely(bt)) \ - __trace_note_message(bt, fmt, ##__VA_ARGS__); \ + __trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\ } while (0) +#define blk_add_trace_msg(q, fmt, ...) \ + blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__) #define BLK_TN_MAX_MSG 128 static inline bool blk_trace_note_message_enabled(struct request_queue *q) @@ -82,6 +86,7 @@ extern struct attribute_group blk_trace_attr_group; # define blk_trace_startstop(q, start) (-ENOTTY) # define blk_trace_remove(q) (-ENOTTY) # define blk_add_trace_msg(q, fmt, ...) do { } while (0) +# define blk_add_cgroup_trace_msg(q, cg, fmt, ...) do { } while (0) # define blk_trace_remove_sysfs(dev) do { } while (0) # define blk_trace_note_message_enabled(q) (false) static inline int blk_trace_init_sysfs(struct device *dev) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index e90974ed4532..7724de18d2fe 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -154,7 +154,8 @@ static void trace_note_time(struct blk_trace *bt) local_irq_restore(flags); } -void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) +void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg, + const char *fmt, ...) { int n; va_list args; @@ -178,7 +179,14 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); va_end(args); + if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) + blkcg = NULL; +#ifdef CONFIG_BLK_CGROUP + trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, + blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL); +#else trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL); +#endif local_irq_restore(flags); } EXPORT_SYMBOL_GPL(__trace_note_message); @@ -375,7 +383,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, return PTR_ERR(msg); bt = filp->private_data; - __trace_note_message(bt, "%s", msg); + __trace_note_message(bt, NULL, "%s", msg); kfree(msg); return count; -- 2.20.1